Beam scanning apparatus and optical apparatus including the same

Abstract

A beam scanning apparatus includes a light source configured to emit light, and a reflective phased array device configured to reflect the light emitted from the light source and incident on the reflective phased array device, and electrically adjust a reflection angle of the reflected light reflected by the reflective phased array device, wherein the light source and the reflective phased array device are disposed such the light is incident on the reflective phased array device at an incidence angle with respect to a normal of a reflective surface of the reflective phased array device.

What is claimed is: 
     
       1. A beam scanning apparatus comprising:
 at least one light source configured to emit light; and 
 a reflective phased array device configured to reflect the light emitted from the at least one light source and incident on the reflective phased array device, and electrically adjust a reflection angle of reflected light reflected by the reflective phased array device based on an applied voltage from a voltage source, 
 wherein the reflective phased array device comprises an electrode layer, an active layer disposed on the electrode layer, an insulating layer disposed on the active layer, and a plurality of antenna layers disposed on the insulating layer, 
 wherein each of the plurality of antenna layers extends in a first direction and the plurality of antenna layers are disposed at predetermined intervals in a second direction perpendicular to the first direction, 
 wherein the at least one light source and the reflective phased array device are disposed such that the light is incident on the reflective phased array device at an incidence angle with respect to a normal of a reflective surface of the reflective phased array device in a direction parallel to the second direction, 
 wherein, when the incidence angle is θi and a reflection angle of central reflected light with respect to the normal of the reflective surface of the reflective phased array device is θr, the reflective phased array device is configured such that a maximum steering angle θs of the reflective phased array device with respect to the central reflected light satisfies θr−θs>−θi, and 
 wherein the central reflected light is light reflected by the reflective phased array device when no voltage is applied to the reflective phased array device. 
 
     
     
       2. The beam scanning apparatus of  claim 1 , wherein the at least one light source and the reflective phased array device are disposed such that the light incident on the reflective phased array device and the reflected light reflected by the reflective phased array device do not overlap each other. 
     
     
       3. The beam scanning apparatus of  claim 1 , wherein the electrode layer comprises a conductive metal configured to reflect the light emitted from the at least one light source. 
     
     
       4. The beam scanning apparatus of  claim 1 , wherein each of the plurality of antenna layers has a fishbone shape and comprises a first antenna portion extending in the first direction and a plurality of second antenna portions disposed along the first direction and extending in the second direction from the first antenna portion. 
     
     
       5. The beam scanning apparatus of  claim 4 ,
 wherein the reflected light comprises directly reflected light that is directly reflected by the reflective phased array device and resonated scattered light that is generated based on resonance in each of the plurality of antenna layers of the reflective phased array device, and 
 wherein a length of each of the plurality of second antenna portions in the first direction is determined such that an intensity of the directly reflected light is substantially equal to an intensity of the resonated scattered light. 
 
     
     
       6. The beam scanning apparatus of  claim 5 , wherein the length of each of the plurality of second antenna portions in the first direction is determined based on the incidence angle of the light. 
     
     
       7. The beam scanning apparatus of  claim 1 ,
 wherein the reflected light comprises directly reflected light that is directly reflected by the reflective phased array device and resonated scattered light that is generated based on resonance in each of the plurality of antenna layers of the reflective phased array device, 
 wherein at least one of an interval between the plurality of antenna layers in the second direction and an antenna period is determined such that an intensity of the directly reflected light is substantially equal to an intensity of the resonated scattered light, and 
 wherein the antenna period is a length at which the plurality of antenna layers are repeated in the second direction. 
 
     
     
       8. The beam scanning apparatus of  claim 7 , wherein at least one of the interval between the plurality of antenna layers and the antenna period is determined based on the incidence angle of the light incident on the reflective phased array device. 
     
     
       9. The beam scanning apparatus of  claim 7 , wherein at least one of the interval between the plurality of antenna layers and the antenna period is less than an interval between the plurality of antenna layers or an antenna period corresponding to light perpendicularly incident on the reflective phased array device. 
     
     
       10. The beam scanning apparatus of  claim 7 , wherein as the incidence angle of the light incident on the reflective phased array device increases, at least one of the interval between the plurality of antenna layers or the antenna period decreases. 
     
     
       11. The beam scanning apparatus of  claim 7 , wherein at least one of an interval between the plurality of antenna layers and the antenna period is determined such that the intensity of the directly reflected light is substantially equal to the intensity of the resonated scattered light based on the applied voltage to the reflective phased array device and a wavelength of the light incident on the reflective phased array device. 
     
     
       12. The beam scanning apparatus of  claim 1 , wherein the at least one light source and the reflective phased array device are disposed such that a travelling direction of the light incident on the reflective phased array device is parallel to the first direction. 
     
     
       13. The beam scanning apparatus of  claim 12 , wherein the at least one light source comprises:
 a first light source configured to emit first incident light that is incident on the reflective phased array device at a first incidence angle with respect to the normal of the reflective surface of the reflective phased array device; and 
 a second light source configured to emit second incident light that is incident on the reflective phased array device at a second incidence angle different from the first incidence angle. 
 
     
     
       14. The beam scanning apparatus of  claim 13 , wherein first reflected light generated by the first incident light reflected by the reflective phased array device travels at a first reflection angle with respect to the normal of the reflective surface of the reflective phased array device, and second reflective light generated by the second incident light reflected by the reflective phased array device travels at a second reflection angle, different from the first reflection angle, with respect to the normal of the reflective surface of the reflective phased array device, and
 wherein the beam scanning apparatus further comprises an optical element disposed on a travelling path of the second reflective light and configured to change a travelling direction of the second reflective light. 
 
     
     
       15. The beam scanning apparatus of  claim 1 , wherein the at least one light source and the reflective phased array device are disposed such that the reflective phased array device is further configured to reflect the light where a scanning plane comprising reflected light reflected by the reflective phased array device at different angles is perpendicular to the first direction. 
     
     
       16. A beam scanning apparatus comprising:
 at least one light source configured to emit light; and 
 a reflective phased array device configured to reflect the light emitted from the at least one light source and incident on the reflective phased array device, and electrically adjust a reflection angle of reflected light reflected by the reflective phased array device based on an applied voltage from a voltage source, 
 wherein the reflective phased array device comprises an electrode layer, an active layer disposed on the electrode layer, an insulating layer disposed on the active layer, and a plurality of antenna layers disposed on the insulating layer, 
 wherein each of the plurality of antenna layers extends in a first direction and the plurality of antenna layers are disposed at predetermined intervals in a second direction perpendicular to the first direction, 
 wherein the at least one light source and the reflective phased array device are disposed such that the light is incident on the reflective phased array device at an incidence angle with respect to a normal of a reflective surface of the reflective phased array device in a direction parallel to the second direction, and 
 wherein, when an interval between the plurality of antenna layers in the second direction or an antenna period is p, the incidence angle is θi, where λ is a wavelength of the light, the reflective phased array device is configured such that a maximum steering angle θs satisfies θi>0.5 θs and θs=sin−1(λ/2p). 
 
     
     
       17. A beam scanning apparatus comprising:
 at least one light source configured to emit light; and 
 a reflective phased array device configured to reflect the light emitted from the at least one light source and incident on the reflective phased array device, and electrically adjust a reflection angle of reflected light reflected by the reflective phased array device based on an applied voltage from a voltage source, 
 wherein the reflective phased array device comprises a plurality of antenna resonators respectively comprising an electrode layer and an active layer, each of the plurality of antenna resonators being independently driven, 
 wherein the at least one light source and the reflective phased array device are disposed such that the light is incident on the reflective phased array device at an incidence angle with respect to a normal of a reflective surface of the reflective phased array device, 
 wherein the reflected light comprises directly reflected light that is directly reflected by the reflective phased array device and resonated scattered light that is generated based on resonance in each of the plurality of antenna resonators of the reflective phased array device, and 
 wherein an intensity of the directly reflected light is substantially equal to an intensity of the resonated scattered light. 
 
     
     
       18. The beam scanning apparatus of  claim 17 , wherein each of the plurality of antenna resonators further comprises:
 an insulating layer disposed on the active layer opposite to the electrode layer; and 
 an antenna layer disposed on the insulating layer opposite to the active layer. 
 
     
     
       19. The beam scanning apparatus of  claim 18 , wherein the antenna layer has a fishbone shape and comprises a first antenna portion extending in a first direction and a plurality of second antenna portions disposed along the first direction and extending in a second direction from the first antenna portion,
 wherein a length of each of the plurality of second antenna portions in the first direction is determined such that the intensity of the directly reflected light is substantially equal to the intensity of the resonated scattered light, and 
 wherein the length of each of the plurality of second antenna portions in the first direction is determined based on the incidence angle of the light. 
 
     
     
       20. The beam scanning apparatus of  claim 18 , wherein the antenna layer comprises a plurality of antenna layers,
 wherein each of the plurality of antenna layers extends in a first direction and are disposed at predetermined intervals in a second direction perpendicular to the first direction, 
 wherein at least one of an interval between the plurality of antenna layers in the second direction and an antenna period is determined such that the intensity of the directly reflected light is substantially equal to the intensity of the resonated scattered light, and 
 wherein the antenna period is a length at which the plurality of antenna layers are repeated in the second direction, and 
 wherein at least one of the interval between the plurality of antenna layers and the antenna period is determined based on the incidence angle of the light incident on the reflective phased array device. 
 
     
     
       21. A beam scanning apparatus comprising:
 at least one light source configured to emit light; and 
 a reflective phased array device configured to reflect the light emitted from the at least one light source and incident on the reflective phased array device, and electrically adjust a reflection angle of reflected light reflected by the reflective phased array device based on an applied voltage from a voltage source, the reflective phased array device comprising a plurality of antenna layers, 
 wherein the reflective phased array device comprises a plurality of antenna resonators respectively comprising an electrode layer and an active layer, each of the plurality of antenna resonators being independently driven, 
 wherein the at least one light source and the reflective phased array device are disposed such the light is incident on the reflective phased array device at an incident angle with respect to a normal of a reflective surface of the reflective phased array device, 
 wherein the reflected light comprises directly reflected light that are reflected by the reflective phased array device and resonated scattered light that are generated based on resonance in each of the plurality of antenna resonators of the reflective phased array device, and 
 wherein at least one of an interval between the plurality of antenna layers or an antenna period is determined such that an intensity of the directly reflected light is substantially equal to an intensity of the resonated scattered light.